De Havilland DHC-2 Beaver

The wind strength and sea state at the time of the occurrence were not ideal for floatplane operations, particularly given the pilot's relative lack of experience in open water operations. In comparison, it was unlikely the non-standard floats contributed significantly to the development of the accident. The loss of directional control suggests a lower than ideal pitch attitude at touchdown, a configuration which reduces a floatplane's directional stability. The pilot's use of a distress beacon for search and rescue purposes was appropriate, however the timeliness of his rescue from the upturned aircraft can be attributed to the effectiveness of the company's flight monitoring system and subsequent search and rescue actions.

The pilot's failure to use a checklist to ensure the airplane was in the proper landing configuration, which precipitated an inadvertent water landing on amphibious floats with the wheels extended. A factor contributing to the accident was the pilot's failure to secure the cargo in the aft cabin.

The pilot's failure to maintain clearance from terrain while maneuvering inside a box/blind canyon, resulting in an in-flight collision with terrain. A factor contributing to the accident was the box/blind canyon.

Findings as to Causes and Contributing Factors:
1. The seaplane stalled at an altitude that did not allow the pilot time to recover from the stall.
2. The stall occurred in circumstances conducive to illusions created by drift.
Findings as to Risks:
1. The aircraft was not equipped with a stall warning device, which could have alerted the pilot to the onset of a stall.
2. The chances of surviving the impact would have been improved if the front seat occupants had been wearing their shoulder harnesses as prescribed by aviation regulations.
3. Life jackets were available, but the occupants who evacuated the aircraft do not seem to have had time to find, retrieve, and don them.
4. The emergency locator transmitter was not capable of emitting a distress signal because a short circuit occurred when the antenna came into contact with the water.

Findings as to Causes and Contributing Factors:
1. The pilot abandoned his attempt to fly through the pass because of unsuitable weather conditions. He flew into a confined area that required him to manoeuvre the aircraft aggressively to avoid the rising terrain, causing the aircraft to stall.
2. The aircraft weight exceeded the certificated MAUW, and the CG was outside the floatplane aft limit. The out-of-limit weight and balance aggravated aerodynamic stall and produced rapid and
uncontrolled aircraft attitudes from which the pilot could not recover before striking the trees.
3. Basic weight and balance of the aircraft was incorrectly recorded in several aircraft documents, leading to remarkable discrepancies in take-off weight and CG calculations. As a result, a pilot could not calculate an accurate weight and balance. In certain conditions, calculations erroneously showed that the aircraft was below maximum allowable gross weight.
Findings as to Risk:
1. The practice of using a non-standard passenger weight led to inaccurate take-off weight calculations and provided an estimated total passenger weight that was 185 pounds less than actual.
2. Weight and balance calculations performed using inaccurate figures would not have revealed that the aircraft was overloaded until it was approximately 450 pounds beyond the maximum limit.
3. Aircraft weight exceeded the maximum allowable gross weight, and the CG was outside the aft CG limit. This weight and balance combination placed the aircraft outside the manufacturer’s
original design envelope, to where slow speed and stall handling characteristics are neither proven nor certificated.
4. Cargo was not secured by the available cargo restraint and might have shifted during aircraft manoeuvring. Such cargo movement would have exacerbated the effects of the existing aft CG and likely increased the level of injury to the occupants.
Other Findings:
1. The pilot chose to fly above cloud in accordance with the visual flight rules and could not descend through the cloud at his intended landing site.
2. The Alaska cargo door installation increases the volume of the cargo compartment. The installation is thereby conducive to larger loads being stowed farther aft and possible overloading of the cargo compartment.
3. The DHC-2 Beaver is not equipped with an aural or visual stall warning system, nor is it required by regulation. Warning of an impending stall is dependent on juddering or some other aerodynamic indication.